Background: The evaluation of muscle pain and sensitivity by manual palpation is an important part of the clinical examination in patients with myalgia. However, the effects of clinical experience and visual feedback on palpation of the masticatory muscles with or without a palpometer are not known.

Objective: To estimate the effects of clinical experience and visual feedback on the accuracy of palpation in standardized settings.

Methods: Thirty-two dentists (age 35 ± 11 years) classified as either specialists (n = 16) or generalists (n = 16) participated in this experiment. All dentists were instructed to target force levels of 500- or 1000-gf, as determined on an electronic scale using either standardized palpometers or manual palpation (MP). All dentists participated in four different tests: MP, MP with visual feedback (MPVF), palpometer (PAL) and PAL with visual feedback (PALVF). Actual force values for each type of palpation from 0 to 2, 2 to 5 and 0 to 5 s were analysed by calculating target force level.

Results: The relative differences during 2-5 and 0-5 s with 1000 gf were significantly lower for generalists than for specialists (p < .05). In generalists and specialists, the coefficients of variation and the relative differences during 2-5 s were significantly lower for PAL and PALVF than for MP (p < .05).

Conclusions: These findings suggest that the use of a palpometer, but not clinical experience with palpation of masticatory muscles, increases the accuracy of palpation, and ≥2 s of palpation with a palpometer is optimal for masticatory muscles.

AIM: The aim of the study was to evaluate the 5 years clinical outcomes associated with implant-level connection (IL) versus abutment-level connection (AL) for implants with an internal conical connection (ICC) supporting a screw-retained fixed partial denture.

MATERIALS AND METHODS: Fifty patients with 119 implants were randomly allocated to either the AL or IL group. Radiographic (Marginal bone loss) and clinical outcomes (Bleeding on Probing, probing pocket depth, plaque accumulation, incidence of peri-implantitis and peri-implant mucositis as well as prosthetic complications) were collected and compared at 1, 2, 3, and 5 years. A linear mixed model was used to evaluate the differences between groups.

RESULTS: Five years after treatment, the MBL change was not significantly different between the groups at any point. The MBL was 0.23 ± 0.64 mm (AL) and 0.23 ± 0.29 mm (IL). The bleeding on Probing was 44% (AL) and 45% (IL) (p = .89). The mean probing depth was 2.91 ± 1.01 mm (AL) and 3.51 ± 0.67 mm (IL). This difference between the groups was statistically significant but clinical insignificant. Presence of plaque was slightly higher (p = .06) in the IL group (34.4%) compared with the AL group (26.3%). The overall technical, biological, and prosthetic complication rates were similar between groups. None of the implants developed peri-implantitis during the entire follow-up period.

CONCLUSION: The results of this clinical trial indicated that all clinical and radiographical parameters were clinically comparable between the study groups.

PURPOSE: To investigate the influence of cantilever prosthetic arm on the marginal bone loss (MBL) over time around dental implants supporting short fixed partial dentures (FPDs), in a record-based retrospective study.

METHODS: All cases of 3-unit implant-supported FPDs, supported by 2-3 implants, from the database of cases treated at one specialist clinic were considered for inclusion. Only implants with a minimum of 36 months of radiological follow-up were considered. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built.

RESULTS: One-hundred-thirty-nine patients (64 men, 75 women) with 164 3-unit implant-supported FPDs (333 implants supporting non-cantilevered FPDs, 94 supporting cantilevered FPDs) were included in the study. The patients were followed up clinically and radiographically for a mean of 154.1 ± 78.0 (min-max, 37.3-364.6) and 132.9 ± 77.3 months (min-max, 36.8-329.9), respectively. The total number of marginal bone level double measurements (mesial and distal sides of each implant) was 2909. FPDs with cantilever presented an estimated greater MBL over time compared to FPDs without cantilever. Bruxism, sex (women), implant (modified) surface, and (poor) bone quality were also associated with higher MBL over time.

CONCLUSIONS: The use of a cantilever extension is suggested to negatively affect the bone marginal level over time around implants supporting 3-unit FPDs. Due to the small difference of the estimated MBL over long periods of follow-up between the groups, it is a matter of debate if the observed negative effect may be of clinical significance.

Objectives: The aims of Working Group 1 were to address the role (i) of the buccolingual bone dimensions after implant placement in healed alveolar ridge sites on the occurrence of biologic and aesthetic complications, and (ii) of soft tissue augmentation (STA) on the stability of clinical, radiographic, and patient-related outcomes of implant treatments.Materials and Methods: Two systematic reviews were prepared in advance of the Consensus Conference and were discussed among the participants of Group 1. Consensus statements, clinical recommendations, recommendations for future research, and reflections on patient perspectives were based on structured group discussions until consensus was reached among the entire group of experts. The statements were then presented and accepted following further discussion and modifications as required by the plenary.Results: Dimensional changes of the alveolar ridge occurred after implant placement in healed sites, and a reduction in buccal bone wall thickness (BBW) of 0.3 to 1.8 mm was observed. In healed sites with a BBW of <1.5 mm after implant placement, increased vertical bone loss, and less favorable clinical and radiographic outcomes were demonstrated. Implants with buccal dehiscence defects undergoing simultaneous guided bone regeneration, showed less vertical bone loss, and more favorable clinical and radiographic outcomes, compared to non-augmented dehiscence defects during initial healing. At healthy single implant sites, probing depths, bleeding and plaque scores, and interproximal bone levels evaluated at 1 year, remained stable for up to 5 years, with or without STA. When single implant sites were augmented with connective tissue grafts, either for soft tissue phenotype modification or buccal soft tissue dehiscence, stable levels of the soft tissue margin, and stable or even increased soft tissue thickness and/or width of keratinized mucosa could be observed from 1 to 5 years. In contrast, non-augmented sites were more prone to show apical migration of the soft tissue margin in the long-term. Favorable aesthetic and patient-reported outcomes after STA were documented to be stable from 1 to 5 years.Results: Dimensional changes of the alveolar ridge occurred after implant placement in healed sites, and a reduction in buccal bone wall thickness (BBW) of 0.3 to 1.8 mm was observed. In healed sites with a BBW of <1.5 mm after implant placement, increased vertical bone loss, and less favorable clinical and radiographic outcomes were demonstrated. Implants with buccal dehiscence defects undergoing simultaneous guided bone regeneration, showed less vertical bone loss, and more favorable clinical and radiographic outcomes, compared to non-augmented dehiscence defects during initial healing. At healthy single implant sites, probing depths, bleeding and plaque scores, and interproximal bone levels evaluated at 1 year, remained stable for up to 5 years, with or without STA. When single implant sites were augmented with connective tissue grafts, either for soft tissue phenotype modification or buccal soft tissue dehiscence, stable levels of the soft tissue margin, and stable or even increased soft tissue thickness and/or width of keratinized mucosa could be observed from 1 to 5 years. In contrast, non-augmented sites were more prone to show apical migration of the soft tissue margin in the long-term. Favorable aesthetic and patient-reported outcomes after STA were documented to be stable from 1 to 5 years. Conclusions: It is concluded that dimensional changes of the alveolar ridge occur after implant placement in healed sites and that sites with a thin BBW after implant placement are prone to exhibit less favorable clinical and radiographic outcomes. In addition, it is concluded that STA can provide stable clinical, radiographic, aesthetic, and patient-reported outcomes in the medium and long-term.

Objectives: To assess whether in animals or patients with ≥ 1 tooth extracted, hyaluronic acid (HyA) application results in superior healing and/or improved complication management compared to any other treatment or no treatment.

Materials and methods: Three databases were searched until April 2022. The most relevant eligibility criteria were (1) local application of HyA as adjunct to tooth extraction or as treatment of alveolar osteitis, and (2) reporting of clinical, radiographic, histological, or patient-reported data. New bone formation and/or quality were considered main outcome parameters in preclinical studies, while pain, swelling, and trismus were defined as main outcome parameters in clinical studies.

Results: Five preclinical and 22 clinical studies (1062 patients at final evaluation) were included. In preclinical trials, HyA was applied into the extraction socket. Although a positive effect of HyA was seen in all individual studies on bone formation, this effect was not confirmed by meta-analysis. In clinical studies, HyA was applied into the extraction socket or used as spray or mouthwash. HyA application after non-surgical extraction of normally erupted teeth may have a positive effect on soft tissue healing. Based on meta-analyses, HyA application after surgical removal of lower third molars (LM3) resulted in significant reduction in pain perception 7 days postoperatively compared to either no additional wound manipulation or the application of a placebo/carrier. Early post-operative pain, trismus, and extent of swelling were unaffected.

Conclusions: HyA application may have a positive effect in pain reduction after LM3 removal, but not after extraction of normally erupted teeth.

Clinical relevance: HyA application may have a positive effect in pain reduction after surgical LM3 removal, but it does not seem to have any impact on other complications or after extraction of normally erupted teeth. Furthermore, it seems not to reduce post-extraction alveolar ridge modeling, even though preclinical studies show enhanced bone formation.

Periodontitis is a bacterial-induced disease and for this reason controlling the microbiota is a necessity. Therapy includes self-performed daily oral hygiene in combination with supra- and sub-gingival instrumentation. An adjunctive antimicrobial agent may improve the outcome.Aims To assess whether a chloramine (Perisolv (R)) has an adjunctive effect to non-surgical periodontal therapy and whether non-surgical periodontal therapy affects quality of life.Material and MethodsThirty-eight patients were randomized to a test or a control group. Clinical indices were performed at baseline and at three and twelve months. In the test group, Perisolv (R) was applied initially and after the sub-gingival instrumentation in pathological pockets. Oral health-related quality of life was measured with the Oral Health Impact Profile (OHIP) instrument at baseline and twelve months.Results In both groups, an initial probing pocket depth (PPD) of > 4 mm and bleeding on probing (BOP) were statistically reduced (p < 0.002 and p < 0.002 respectively) at twelve months and after adjustment for Bonferroni. There were no significant differences between the test and the control group in terms of the number of PPD, BOP or plaque index, or in the mean OHIP score.Conclusions Chloramine did not have an adjunctive effect, but the overall therapy was significantly efficacious both clinically and in terms of quality of life.

More than 26,000 children and young people are placed in out-of-home care in Sweden every year. Several studies show that children placed in out of home care have poorer health during childhood and are generally in poorer physical condition later in life. The overall aim of this thesis was to study dental health and dental care in children in out-of-home care (OHC), through registry-based research. Paper I was a registry-based study of dental health care utilisation among young adults who as children had been placed in societal out-of-home care. These young adults had more emergency dental visits and more extractions and fewer regular scheduled dental check-ups than their peers who had never experienced OHC.

Paper II was a systematic review/HTA to evaluate organisational models intended to ensure that children and young people in out-of-home care will receive health and dental care. We were unable to identify any study, of low or medium risk of bias, which examined the effects of organisational models on provision of health and dental care for children and young people in foster care and in institutions.

Papers III and IV were validation studies of the Swedish Quality Registry for Caries and Periodontal Diseases (SKaPa), undertaken to determine the accuracy of the registry and whether it was appropriate for application in the next study (Paper V) and for other research purposes. For dft/DFT, the validation studies showed high agreement between the data in the patient records and the SKaPa registry. However, e/M in deft/DMFT was shown to be uncertain.

Paper V was a registry-based study linking different registries, to investigate dental health and dental care in children in OHC. This study showed that children in OHC have more caries and undergo fewer dental health assessments than those who have never been placed in OHC. There was a difference in dental health examinations before and after the year 2017, with higher frequencies of assessments after the legislative amendment in 2017. However, differences remain.

BACKGROUND: Adherence to antibiotic recommendations and safety aspects of restrictive use are important components when combating antibiotic resistance. The primary aim of this study was to assess the impact of national guidelines on antibiotic prescriptions for bone augmentation procedures among dentists working at three specialized clinics. The secondary aim was to assess the occurrence of postoperative infections.

METHODS: Medical charts of 400 patients treated with bone augmentation were reviewed: 200 in the years 2010-2011 and 200 in 2014-2015. The Swedish national recommendations for antibiotic prophylaxis were published in 2012.

RESULTS: There was a wide variation in antibiotic regiments prescribed throughout the study. The number of patients treated with antibiotic prophylaxis in a single dose of 2 g amoxicillin, and treated as advocated in the national recommendations, was low and decreasing between the two time periods from 25% (n = 50/200) in 2010-2011 to 18.5% (n = 37/200) in 2014-2015. The number of patients not given any antibiotics either as a prophylactic single dose or during the postoperative phase increased (P < 0.001). The administration of a 3-7-days antibiotic prescription increased significantly from 25.5% in 2010-2011 to 35% in 2014-2015. The postoperative infection rates (4.5% and 6.5%) were without difference between the studied periods. Smoking and omitted antibiotic prophylaxis significantly increased the risk of postoperative infection. Logistic regression analyses showed that patient male gender and suffering from a disease were predictive factors for the clinician to adhere to the guidelines.

CONCLUSIONS: After introduction of national recommendations for antibiotic prophylaxis before bone augmentation procedures, the patient group receiving a single preoperative dose decreased while the group not given antibiotic prophylaxis increased. There was no difference in occurrence of postoperative infections between the two time periods. The results indicate a need for educational efforts and strategies for implementation of antibiotic prudence and awareness among surgeons performing bone augmentation procedures.

BACKGROUND: Multivariable prediction models are used in oral health care to identify individuals with an increased likelihood of caries increment. The outcomes of the models should help to manage individualized interventions and to determine the periodicity of service. The objective was to review and critically appraise studies of multivariable prediction models of caries increment.

METHODS: Longitudinal studies that developed or validated prediction models of caries and expressed caries increment as a function of at least three predictors were included. PubMed, Cochrane Library, and Web of Science supplemented with reference lists of included studies were searched. Two reviewers independently extracted data using CHARMS (Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies) and assessed risk of bias and concern regarding applicability using PROBAST (Prediction model Risk Of Bias ASessment Tool). Predictors were analysed and model performance was recalculated as estimated positive (LR +) and negative likelihood ratios (LR -) based on sensitivity and specificity presented in the studies included.

RESULTS: Among the 765 reports identified, 21 studies providing 66 prediction models fulfilled the inclusion criteria. Over 150 candidate predictors were considered, and 31 predictors remained in studies of final developmental models: caries experience, mutans streptococci in saliva, fluoride supplements, and visible dental plaque being the most common predictors. Predictive performances varied, providing LR + and LR - ranges of 0.78-10.3 and 0.0-1.1, respectively. Only four models of coronal caries and one root caries model scored LR + values of at least 5. All studies were assessed as having high risk of bias, generally due to insufficient number of outcomes in relation to candidate predictors and considerable uncertainty regarding predictor thresholds and measurements. Concern regarding applicability was low overall.

CONCLUSIONS: The review calls attention to several methodological deficiencies and the significant heterogeneity observed across the studies ruled out meta-analyses. Flawed or distorted study estimates lead to uncertainty about the prediction, which limits the models' usefulness in clinical decision-making. The modest performance of most models implies that alternative predictors should be considered, such as bacteria with acid tolerant properties.

TRIAL REGISTRATION: PROSPERO CRD#152,467 April 28, 2020.

BACKGROUND: While the dimensional alteration of alveolar bone following tooth extraction have been extensively descripted in the literature, no information is available regarding potential hard and soft tissues changes following implant explantation.

AIM: To evaluate the radiographic bone healing and the horizontal and vertical soft tissue dimensional alterations at implant extraction alveoli, 6 months following implant explantation.

MATERIAL AND METHODS: Data from 31 patients scheduled for extraction of one implant with persisting peri-implantitis despite treatment were analysed. Bone crest level changes and the extent of bone healing at the apical aspect of the implant socket were assessed on the radiographs prior and 6 months following explantation. Regression analyses assessed the impact of various predictors (e.g., bone crest level, presence/absence of buccal bone) on bone level changes. Fisher's exact probability test was applied to assess the difference in probability to have mucosa recession of ≥2 mm in the presence or absence of alveolar buccal bone.

RESULTS: A vertical bone loss of 0.8 mm (standard deviation [SD] = 1.3) of the peri-implant bone crest and a gain of 0.8 mm (SD = 1.1) from the bottom of the peri-implant defect were recorded. Complete healing was noted in the intact implant extraction socket (i.e., the part of the implant not affected by peri-implantitis). A reduction of 0.4 mm (SD = 0.7) of the alveolar mucosa height was recorded in concomitant with a decrease of 0.7 mm (SD = 0.8) of the mucosa width. These alterations were more pronounced in the absence of the alveolar buccal bone.

CONCLUSION: The results of the present explorative study indicated a decrease in the height and width of the alveolar soft and hard tissues following explantation of peri-implantitis affected implants, and these changes were more pronounced in the absence of the buccal bone wall. Nevertheless, the apical portion of the implant alveolus (the intact implant socket) tend to heal with no further bone loss.

The purpose of this technical report is to present two novel experimental implant designs to boost data generation in preclinical in vivo research. Specifically, the report describes the rationale and the components of (1) a two-piece experimental implant suitable for a small animal platform (e.g., the rabbit femur/tibial epiphysis model), consisting of a threaded apical- and a coronal cylindrical piece, which is intended for collecting two types of biomechanical data, and (2) a three-piece experimental implant suitable for a large animal platform (e.g., the mini-pig mandible model), consisting of an apical "wound chamber", which allows the collection of histological/histomorphometrical data, and a middle threaded and coronal cylindrical piece, which also allow the collection of two types of biomechanical data. The increased volume of information generated from a single experiment in a small animal platform, using the proposed two-piece implant design, may assist in a more qualified decision-making process, on whether it is relevant to proceed to further assessment using a large animal platform. Furthermore, the increased volume of information generated in a single animal experiment either in a small or large animal platform, using the proposed two- and three-piece implants, respectively, likely decreases the number of animals otherwise needed for collecting the same information with standard one-piece implants and, thus, contributes to the reduction/refinement elements of the 3R principle.

BACKGROUND/AIM: There are few long-term clinical follow-up studies on human teeth replanted immediately or after storage in a suitable storage medium prior to replantation. This study aimed to assess the risk of ankylosis in avulsed human teeth replanted immediately or after storage in physiological media for a short time.

MATERIAL: Data from 116 patients with 145 replanted avulsed permanent teeth were selected from a comprehensive dental trauma database in Copenhagen University Hospital. The following teeth were selected: Group 1 comprised 36 teeth replanted immediately (dry time <6 min; wet time <6 min). Group 2 comprised 61 teeth replanted after physiologic storage media (saliva and saline) (dry time <6 min; wet time >5 min; wet time ranged from 7 to 170 min, and mean wet time was 59 min). Group 3 (control) included 48 teeth replanted after dry storage (dry time > 60 min).

METHOD: Clinical and radiographic registrations were carried out according to a standardized protocol; follow-up ranged from 7 months to 23 years. Ankylosis was diagnosed by percussion test and radiographs and related to the conditions prior to replantation and stage of root development.

RESULTS: The overall risk of ankylosis was 17.2% [95% CI: 4.61; 29.79] for immediately replanted teeth, 55.3% [95% CI: 42.54; 68.00] for teeth stored in physiologic media before replantation, and 85.7% [95% CI: 75.70; 95.73] for teeth stored dry more than 1 h. Mature teeth showed a significantly higher risk of ankylosis than immature teeth.

CONCLUSION: This clinical long-term study has verified earlier experimental studies showing that immediate reimplantation has the lowest risk of ankylosis. Physiologic storage media are good alternatives that also reduce the risk of ankylosis compared to dry storage, where ankylosis is more likely although not always seen. Mature teeth are significantly more likely to develop ankylosis.

Purpose: To determine the biologic and biomechanical effects of two implant drilling protocols on the cortical bone around implants subjected to immediate loading. Materials and Methods: A total of 48 implants were inserted into the mandibles of six sheep following one of two drilling protocols: undersized preparation (US; n = 24) and nonundersized preparation (NUS; n = 24). Immediately after implant insertion, an abutment was placed on each implant and 36 implants were subjected to 10 sessions of dynamic vertical loads (1,500 cycles, 1 Hz) of 25 N or 50 N. Insertion torque value (ITV) was recorded at implant installation. Resonance frequency analysis (RFA) was measured at implant insertion and at each loading session. Fluorochrome was administered at day 17, and the animals were euthanized after 5 weeks. The removal torque values (RTVs) were measured, and samples underwent histomorphometric, mu CT (microcomputed tomography), and fluorescence image acquisition analyses. The bone volume density (BV/TV), bone-to-implant contact (BIC), bone area fraction occupancy (BAFO), and fluorochrome stained bone surface (MS) were calculated. A linear mixed model analysis was performed, and Pearson paired correlation was calculated. Results: Five implants from the NUS group failed, with a mean ITV of 8.8 Ncm and an RFA value of 57. The mean ITVs for US group and NUS group were 80.5 (+/- 14) Ncm and 45.9 (+/- 25) Ncm, respectively (P < .001). No differences were noted in the RFA values from the time of implant insertion until the end of the study. No differences in RTV, BV/TV, BAFO, or MS were observed between the groups. Intense new bone formation took place in the NUS group implants that were subjected to load. Conclusions: Undersized preparation of cortical bone ensured a greater BIC compared to a nonundersized preparation. Moreover, this study demonstrated that immediate loading did not interfere with the osseointegration process, but loading induced intense new bone formation in the NUS group. It is not recommended to immediately load the implants when the clinically perceived primary stability is lower than an ITV of 10 Ncm and an RFA value of 60.

ObjectivesTemporomandibular disorders (TMDs) is a collective term for pain and functional disturbances related to the jaw muscles and the temporomandibular joint. In contrast to screening for orofacial pain, knowledge is limited on the association between patient-reported outcomes and screening for joint-related functional jaw disturbances. Therefore, our aim was to evaluate the association between a screening question for functional jaw disturbances, and disease-specific out-come measures for functional jaw limitations and oral behaviors.MethodsThis study included 299 individuals (201 women; 20-69 years, median 37.0) in a general population sample from Vasterbotten, Northern Sweden in 2014. A single screening question for functional jaw disturbances "Does your jaw lock or become stuck once a week or more?" was used to categorize individuals as cases or controls. Patient-reported outcomes on functional jaw disturbances were assessed with the 20-item jaw functional limitation scale (JFLS-20) and oral behaviors with the 21-item Oral Behaviors Checklist (OBC-21).ResultsThe strongest predictive probability to have a positive screening outcome was functional jaw limitations related to mobility (AUC(boot) = 0.78, 95 CI:0.71-0.86, P < .001), followed by limitations related to communication (AUC(boot) = 0.74, 95 CI:0.63-0.80, P < .001) and mastication (AUC(boot) = 0.73, 95 CI:0.66-0.81, P < .001). The frequency of oral behaviors was not significantly associated with a positive screening outcome (AUC(boot) = 0.65, 95 CI:0.55-0.72, P = .223).ConclusionsSelf-reported functional limitations, but not oral behaviors, are strongly associated with a single screening question for frequent functional jaw disturbances. This finding provides support for incorporating a question on jaw catching/locking once a week or more in screening instruments for TMDs.

Background and Objectives: Implant-supported single crowns have become a routine approach for the replacement of missing single teeth, being considered as one of the most common ways of rehabilitation when adjacent teeth are healthy. The present retrospective study aimed to investigate the risk factors possibly associated with failure and technical complications of implant-supported single crowns and their supporting implants. Materials and Methods: Patients treated at one faculty (2009-2019) were considered for inclusion. Complications investigated included ceramic fracture/chipping, crown loss of retention/mobility, crown failure/fracture, loosening/loss/fracture of prosthetic screw, and implant failure/fracture. Any condition/situation that led to the removal/replacement of crowns (implant failure not included) was considered prosthesis failure. Univariate/multivariate Cox regression models were used to evaluate the associations between clinical covariates and failure. Results: 278 patients (358 crowns) were included. Mean & PLUSMN; SD follow-up was 56.5 & PLUSMN; 29.7 months. Seven implants (after a mean of 76.5 & PLUSMN; 43.7 months) and twenty crowns (21.3 & PLUSMN; 23.5 months) failed. The cumulative survival rate (CSR) for crowns was 93.5% after 5, remaining at 92.2% between 6 and 11 years. The most common reasons for crown failure were porcelain large fracture (n = 6), crown repeatedly loose (n = 6), and porcelain chipping (n = 5). Men and probable bruxism were identified in the Cox regression model as being associated with crown failure. The most common observed technical complications were mobility of the crown and chipping of the ceramic material, with the latter being observed even in crowns manufactured of monolithic zirconia. Cases with at least one technical complication (not considering loss of screw hole sealing) were more common among probable bruxers than in non-bruxers (p = 0.002). Cases of ceramic chipping were more common among bruxers than in non-bruxers (p = 0.014, log-rank test). Conclusions: Probable bruxism and patient's sex (men) were factors associated with a higher risk of failure of implant-supported single crowns.

Objectives: To evaluate the cephalometric effects of premolar extraction on skeletal and dental parameters, and on the soft tissues, in patients subsequently treated with fixed appliances. Prevalence and severity of external apical root resorption due to premolar extraction were also examined.Materials and methods: The dental records of 79 patients treated with fixed appliances were retrieved (groups: extraction, n = 19; non-extraction, n = 60). Pre- and post-treatment statuses of skeletal, dentoalveolar, and soft tissue variables were analyzed on lateral cephalograms to determine change. Periapical radiographs of the maxillary incisors were assessed for external apical root resorption using the Levander & Malmgren index. The t-test, Mann-Whitney U test, chi-squared test, and Kruskal-Wallis test were used to analyze the data. Significance was set at p < .05.Results: Changes in the protrusion and proclination of the incisors and in lip position were significantly different between the groups. Prevalence of external apical root resorption in the two groups was similar.Conclusions: Our findings suggest that extraction therapy affects dentoalveolar traits but not jaw position, nor the risk of root resorption, in patients treated with fixed appliances

Background/Aim: To analyse, from the perspective of adults with a history of sexual abuse, the impact of the experience on their general health and well-being.Material and Methods: The participants comprised 12 strategically selected informants (10 women), aged 19-56; all sexually abused during child- and/or adulthood. They were interviewed in-depth and encouraged to describe the impact of the sexual abuse on their daily lives. The consequences of sexual abuse on oral health have previously been reported. The interviews were recorded digitally, transcribed verbatim and analysed according to qualitative content analysis with an inductive approach.Results: The overall theme illustrating the latent content was Sexual abuse experience-limiting long-term consequences, always present in body and mind. The first category covering the manifest content was 'A lost foothold', with two subcategories: (i) emotional repercussions and (ii) physical health repercussions. The second category was 'The significance of distance to trauma', with two subcategories (i) keeping a distance and tending to escape and (ii) processing the trauma experience-a struggle towards balance.Conclusions: A history of sexual abuse cannot be understood in isolation: the long-term repercussions pervade daily life. However, after disclosure of the abuse and processing the trauma, it is possible to ameliorate some of the negative effects. In this context, the dental setting emerges as a potentially important venue for disclosure as almost every person, sooner or later, visits the dentist.

ObjectiveThe aim was to identify caries active individuals among adults by using a trajectory model of longitudinal data from the Swedish national registry (SKaPa) and comparing them with published data from the Dunedin cohort.Materials and methodsData from two different age groups (30- and 40-year-olds) followed for 10 years were retrieved from SKaPa and were compared with published longitudinal birth-cohort data from the Dunedin study. Using the trajectory model, the subjects were divided into three different trajectories according to their caries development over time (i.e. high, 15%; moderate, 45%; low, 40%).ResultsCaries experience, as measured by mean decayed, missing, and filled surfaces (DMFS) index, revealed significant differences among the three trajectories in both age groups. The patterns were similar to those observed in the Dunedin cohort. The mean increase in DMFS during the 10-year follow-up period from SKaPa was significantly higher for the high trajectories in both age groups compared with the moderate and low trajectories.ConclusionsThe method using three trajectories for presentation of caries experience over time, may be a useful tool to identify subjects with different disease activities. Identification of subjects in the high caries experience trajectory may increase the possibility to explore and evaluate more effective caries prevention for this group in the future.

Aim: To investigate the association between periodontitis and lung function in the Malmo Offspring Dental Study.Materials and Methods: In all 1001 individuals (49.9% female, mean age: 44.6) from Malmo Offspring Dental Study were included. Periodontitis was assessed by a full-mouth examination protocol including bleeding on probing and classified according to the American Academy of Periodontology/Center for Disease Control definitions. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were expressed as absolute values and %predicted according to Global Lung Function Initiative reference values. FEV1, FVC and FEV1/FVC were analysed in relation to periodontal status using linear regression.Results:Severe periodontitis was found in 7% of the population. Adjusted regression models showed significant associations between lung function and severe periodontitis with 2.1 unit lower FEV1/FVC ratio (95% CI: -3.91, -0.23) and odds ratio (adjusted) of 2.56 (95% CI: 1.40, 4.75, p = .003) for airflow obstruction (FEV1/FVC less than the lower limit of normal) if having severe periodontitis. Lower values of %predicted FEV1 and %predicted FVC, but not FEV1/FVC, were found in individuals with >25% bleeding on probing.Conclusions: Severe periodontitis was associated with lower FEV1/FVC ratio and airflow obstruction in the present cohort. More large-scale prospective studies and intervention studies are required for a comprehensive evaluation.

This thesis investigates responses to external cues in oral bacteria on a molecular level. Paper I maps Ser/Thr/Tyr phosphorylated proteins in relation to the general proteome in an oral commensal streptococcus (Streptococcus gordonii DL1). The identified phosphoproteins were involved in various bacterial processes, several associated to dysbiosis and development of biofilm-induced disease. Comparison against phosphoproteomes of other bacteria showed many similarities. This is of interest for the identification of shared phosphorylation profiles. 

Paper II studies differences between the S. gordonii DL1 general proteomes in planktonic and biofilm growth phases, and the regulatory effects of salivary mucin MUC5B on protein expression in the biofilm cells. Regulations in protein expression between the different growth conditions provides insights in bacterial mechanisms for adaptation to the biofilm lifestyle. 

Paper III examines the regulatory roles of salivary MUC5B on biofilm attachment and metabolic output in two clinical isolates of oral commensals, S. gordonii CW and Actinomyces naeslundii CW. S. gordonii facilitated adhesion of A. naeslundii to MUC5B during early attachment. Both bacteria were also able to utilize MUC5B as a sole nutrient source during early biofilm formation, individually and synergistically in a dual species biofilm. The specific responses elicited by MUC5B in paper II-III seem to promote commensal colonization while down-regulating dysbiosis-related biofilm activities. 

Microbiological studies are often focused on dysbiosis and development of disease. However, mechanisms that promote eubiosis are equally important to understand how health can be maintained. Findings associated with responses to external cues in oral bacteria may contribute to future development of novel preventative strategies and identification of predictive biomarkers for oral health. 

Bacterial metabolism in oral biofilms is comprised of complex networks of nutritional chains and biochemical regulations. These processes involve both intraspecies and interspecies networks as well as interactions with components from host saliva, gingival crevicular fluid, and dietary intake. In a previous paper, a large salivary glycoprotein, mucin MUC5B, was suggested to promote a dental health-related phenotype in the oral type strain of Streptococcus gordonii DL1, by regulating bacterial adhesion and protein expression. In this study, nuclear magnetic resonance-based metabolomics was used to examine the effects on the metabolic output of monospecies compared to dual species early biofilms of two clinical strains of oral commensal bacteria, S. gordonii and Actinomyces naeslundii, in the presence of MUC5B. The presence of S. gordonii increased colonization of A. naeslundii on salivary MUC5B, and both commensals were able to utilize MUC5B as a sole nutrient source during early biofilm formation. The metabolomes suggested that the bacteria were able to release mucin carbohydrates from oligosaccharide side chains as well as amino acids from the protein core. Synergistic effects were also seen in the dual species biofilm metabolome compared to the monospecies, indicating that A. naeslundii and S. gordonii cooperated in the degradation of salivary MUC5B. A better understanding of bacterial interactions and salivary-mediated regulation of early dental biofilm activity is meaningful for understanding oral biofilm physiology and may contribute to the development of future prevention strategies for biofilm-induced oral disease.

IMPORTANCE: The study of bacterial interactions and salivary-mediated regulation of early dental biofilm activity is of interest for understanding oral microbial adaptation to environmental cues and biofilm maturation. Findings in oral commensals can prove useful from the perspectives of both oral and systemic health of the host, as well as the understanding of general microbial biofilm physiology. The knowledge may provide a basis for the development of prognostic biomarkers, or development of new treatment strategies, related to oral health and disease and possibly also to other biofilm-induced conditions. The study is also an important step toward developing the methodology for similar studies in other species and/or growth conditions.

Aim: To assess whether oral health problems affect disease-specific quality of life (QoL) of inflammatory bowel disease (IBD) patients, and vice versa, whether IBD affects oral-health-related QoL. Materials and Methods: Individuals reporting IBD and matched controls were surveyed on general anamnestic information, oral-health-related questions and the Oral Health Impact Profile (OHIP)-5. IBD patients were additionally surveyed on years since diagnosis, disease activity and severity as well as health-related QoL (Short Inflammatory Bowel Disease Questionnaire, sIBDQ). OHIP-5 and sIBDQ were defined as primary outcome parameters, and several predictors and confounders were used in adjusted univariable and multivariable regression analyses. Results: Answers from 1108 IBD patients and 3429 controls were analysed. Compared with controls, IBD patients reported significantly more frequently an oral impact on daily life and worse oral-health-related QoL, with Crohn's disease (CD) patients being more severely affected than ulcerative colitis (UC) patients. The diagnosis of UC and CD, having <20 teeth, severe periodontitis and stressful daily-life experience were associated with a higher prevalence of poor oral-health-related QoL. Among IBD patients, an impaired IBD-specific, health-related QoL was significantly associated with the diagnosis of CD and depression, IBD activity and severity, having <20 teeth, presence of oral lesions and stressful daily-life experience, while a longer time since diagnosis was significantly associated with an improved IBDspecific, health-related QoL. Conclusions: The results of the present study indicate, for the first time, that oral health problems are associated with an impairment of IBD-specific health-related QoL, and vice versa, IBD is associated with an impaired oral health-related QoL. This emphasizes the potential advantages of including dental professionals in the multi-disciplinary treatment teams of IBD patients.

The purpose of the present systematic review was to investigate the influence of bisphosphonates (BPs) on the dental implant failure rate and marginal bone loss (MBL). An electronic search was undertaken in three databases, plus a manual search of journals. Meta-analyses were performed, besides a meta-regression in order to verify how the log odds ratio (OR) was associated with follow-up time. The five- and ten-year estimated implant survivals were calculated. The review included 33 publications. Altogether, there were 1727 and 21,986 implants placed in patients taking and not taking BPs, respectively. A pairwise meta-analysis (26 studies) showed that implants in BP patients had a higher failure risk in comparison to non-BP patients (OR 1.653, p = 0.047). There was an estimated decrease of 0.004 in log OR for every additional month of follow-up, although it was not significant (p = 0.259). The global estimated implant survival in patients taking BPs after 5 and 10 years was 94.2% (95% CI, 94.0-94.4) and 90.1% (95% CI, 89.8-90.3), respectively. It was not possible to make any reliable analysis concerning MBL, as only two studies reported MBL results separated by groups. There is a 65.3% higher risk of implant failure in patients taking BPs in comparison to patients not taking this class of drugs.

Apical periodontitis is a very common condition. Epidemiological research suggests that nearly 50% of the global adult population may have had at least one affected tooth and that approximately 40% of root-filled teeth may be associated with apical periodontitis. Since apical periodontitis is caused by microorganisms in the root canal system, every measure taken to reduce the microbial burden during treatment is of importance. The high prevalence of apical periodontitis associated with root-filled teeth suggests that dentists in general may have problems eliminating microorganisms in the root canals and avoiding contamination of the root canals when performing endodontic treatments. 

Most non-surgical endodontic treatments are performed by general dentists. It can be assumed that improvement of endodontic infection control in general dentistry could have a positive impact on the overall outcome of endodontic treatments. The aim of this project was to render a better understanding of endodontic infection control in general dentistry. 

Study I and II consisted of a two-folded cross-sectional questionnaire regarding general dentists’ endodontic infection control measures, sources of knowledge, and self-assessed skills. Study III and V consisted of two cross-sectional mixed methods surveys regarding dental health care workers’ experiences during the COVID-19 pandemic, and perceived barriers and facilitators to hand hygiene adherence. Study IV was a prospective observational study which evaluated endodontic operative field asepsis by assessing general dentists’ ability to reduce the contamination to a non-cultivable level.

The vast majority reported using a dental dam and most disinfected the endodontic operative field. However, one in 10 did not use hand disinfectant at all during endodontic treatments. More than half of the respondents did not know, or did not believe, that the initial diagnosis affected the outcome of their endodontic treatments, indicating an underestimation of microbiological factors’ impact on treatment outcome. The majority graded their endodontic treatment outcome and their infection control adherence as good, though several admitted not fully adhering to the infection control guidelines. The clinical study found relatively high levels of contamination on the operative field in general dentistry, which indicates poor aseptic control.

Knowledge, education, and a supportive work environment were perceived as facilitators to infection control. Recurring themes regarding barriers were a lack of training and performance feedback, conflicting messages and conflicting demands, and lack of resources (mainly time). Several respondents reported situations where they had felt pressured to make compromises with their infection control measures.  Most based their endodontic management of patients on what they had been taught during their undergraduate training. A third of the general dentists had not attended any continuing endodontic education. 

The results from the included studies show that although dental professionals may have the intention to adhere to infection control guidelines, they are influenced by various other factors, which may result in nonadherence. There are also indications that the awareness of the risks of contamination occurring during treatment, and the subsequent negative impact contamination may have on treatment outcome, may be lacking. Although both dentists and other dental health care workers graded their knowledge and performance of, for example hand hygiene, as good, several other responses indicated their estimations may be misestimations. 

Further research into what affects endodontic infection control performance is needed, particularly regarding hand hygiene. Additional attention must be paid to the settings in which general dentists operate, as the ability to choose different measures may be limited by environmental and organizational factors. The future challenge is to raise awareness in general dentistry about the microbiological aspects of endodontic treatments and the critical importance of infection control. It would be of value to add more observational data to compare views with what is performed in clinical practice.

A successful outcome of endodontic treatment is strongly associated with well-performed treatment procedures. A prerequisite for satisfactory treatment is access to the root canals via an adequate access cavity preparation that is correctly positioned, of suitable size, and with straight-line access to the canals. After gaining access to the root canals the root canal working length is determined by an electronic apex locator combined with radiographs, preferably after coronal flaring. The root canals are then cleaned and shaped, and in most cases rotary or reciprocating nickel-titanium instruments can be used. This is performed in conjunction with the use of an irrigation solution, usually a low concentration of sodium hypochlorite. Once the chemo-mechanical instrumentation has been thoroughly performed, filling of the root canals is the next essential step. A good quality root filling should end within 2 mm from the radiographic apex without any voids. This is of significant importance for a successful outcome of the treatment, while the materials and techniques appear less important. Lastly, the tooth should be permanently restored as soon as possible after the root filling, to prevent fracture and reinfection.

Provided that the treatment procedures have been adequately performed, under aseptic conditions,  high success rates can be expected.

BACKGROUND: It is not clear whether Viridans Group Streptococcal Infective Endocarditis (VGS-IE) among individuals at high risk is more frequent following bacteraemia caused by invasive dental procedures (IDPs) than after daily bacteraemia caused by chewing and tooth brushing. The aim of this nested study was to assess if VGS-IE was temporally associated with IDPs in a national cohort of individuals at high risk.

METHODS: This nested case-control and case-crossover study was based on a Swedish national cohort study of 76,762 individuals at high risk of IE due to complex congenital heart disease, prosthetic heart valve or previous IE. Participants were living in Sweden between July 1st, 2008 and January 1st, 2018. The frequency of IDPs during the 3 months before VGS-IE was calculated and compared to controls (sampled 1:10). A case-crossover study was conducted to account for residual confounders. Participants were identified using the national patient register, and IDPs were identified using the national dental health register.

FINDINGS: 98,247 IDPs were carried out in the cohort during the study period: 624 occasions of oral surgery, 44,190 extractions and 53,433 sessions of subgingival scaling. The study could not confirm that IDPs were more common among cases (4.6%) than controls (4.1%), OR = 1.22 [95% Confidence Interval (CI) 0.64-2.3], or during case- (3.3%) than reference periods (3.8%), OR = 0.89 [95% CI: 0.68-1.17]. Restricting the analysis to the period when cessation of antibiotic prophylaxis for the prevention of IE in Swedish dentistry was recommended, from the 1st of October 2012 to the 1st of January 2018, did not alter the results of the case-control study: OR 0.64, 95% CI: 0.20-2.09, or the case-crossover study: OR 0.58, 95% CI: 0.15-2.19.

INTERPRETATION: The study could not confirm that VGS-IE is associated with IDPs among individuals at high risk. A study with larger sample size could clarify whether there is a lack of association. The finding of a small (<5%) proportion of cases temporally associated with IDPs is similar to that of the previous large-scale study on IDPs and VGS-IE.

FUNDING: Funding was provided by the Board of doctoral education at Karolinska Institutet, the Public Health Agency of Sweden, Folktandvården Stockholm AB, Steering Group for Collaborative Odontological Research at Karolinska Institutet and Stockholm City County, and the Swedish Dental Association.

BACKGROUND: Temporomandibular disorders (TMD) are common and therefore managed by dentists on a daily basis. However, patients with TMD consistently go undetected and therefore untreated in dentistry. The reasons for these shortcomings have not been fully explored, specifically with regard to patients' perspectives. Therefore, this study aimed to explore patients' experiences of TMD and related treatment, with special focus on the experiences of having TMD, factors related to seeking care, and perspectives on received treatment.

METHODS: Purposive sampling was used to recruit adult patients at the Public Dental Health services (PDHS) in the Region of Västerbotten, Sweden, during 2019. Individual semi-structured interviews were conducted and analysed using Qualitative Content Analysis. Sixteen patients were interviewed (ten women and six men, 20-65 years). The interviews probed the patients' perspectives of having TMD, seeking care, and receiving treatment. All participants were also examined according to the Diagnostic Criteria for TMD (DC/TMD) and qualified for at least one DC/TMD diagnosis.

RESULTS: The data analysis led to the main theme Seeking care when the situation becomes untenable, but dental care fails to meet all needs. The patients expressed worry and social discomfort because of the symptoms but still strived to have an as normal daily life as possible. However, severe symptoms and associated consequences compelled them to seek professional help. Experiences of distrust together with challenges to access the PDHS were identified and related to the patients' unfulfilled expectations.

CONCLUSIONS: Patients' reported experiences indicate that receiving timely and appropriate care is more of an unfulfilled expectation than the current state of management of patients with TMD in dentistry.

Aims: Reflection on a deeper level is recognized as an important skill to learn for undergraduate students since mastering reflection can be helpful throughout their future careers. The aim with this study was to (i) examine if short structured written reflections could stimulate deep reflection among a group of dental students and (ii) explore specifically how the students reflected on clinical experience in relation to uncertainty when assessing the risk for exacerbation of apical periodontitis in root filled teeth.Methods: Short reflections were written by 52 dental students at Malmö University in 2021. All students first answered some questions associated with the risk for exacerbation of apical periodontitis in a case with a root filled tooth with a diffuse widening of the periodontal ligament space. After this, they were asked to write short reflections following prompts developed specifically to stimulate reflection. For each student, the reflections were analyzed and the level of reflection according to the 4Rs framework (Reporting/responding, Relating, Reasoning, Reconstructing) was assessed. The written content in the reflections were analyzed by a qualitative method, Systematic Text Condensation (STC). Results: Thirteen of the students (25%) reached the deepest level of reflection, Reconstructing. Sixteen students (31%), reached only the most superficial level, Report/respond. Two themes about experience and lack of experience were identified in the reflections: Theme 1 “The meaning of clinical experience” and Theme 2 “Differences and similarities”. The themes were subdivided into nine subgroups and described in more detail the relationship between experience and certainty as perceived by the students.Conclusions: A short reflection exercise stimulated deep reflection in a proportion of, but not all, dental students. The students believed that certainty comes with experience even when there is a lack of scientific evidence.

PURPOSE: To compare the failure rates and the prevalence of technical complications between full-coverage tooth-supported monolithic zirconia (MZ) and porcelain-veneered zirconia (PVZ) fixed dental prosthesis, based on a systematic literature review.

METHODS: An electronic search was performed in three databases, supplemented by hand searching. Several statistical methods were used.

RESULTS: Seventy-four publications reported 6370 restorations (4264 PVZ; 2106 MZ; 8200 abutment teeth; 3549 patients), followed up until 152 months. A total of 216 prostheses failed, and survival was statistically significant different between groups. PVZ had higher occurrence of complications than MZ; the difference was especially greater for either minor or major chipping. The difference in prevalence of either minor or major chipping was statistically significant for PVZ prostheses between cementation with glass ionomer and adhesive resin cement (higher), adhesive resin and resin-modified glass ionomer cement (RMGIC, higher), and between RMGIC (higher) and glass ionomer cement. For MZ the difference was significant only for minor chipping between RMGIC (higher) and adhesive resin cement. Abutment teeth to PVZ prostheses more often lost vitality. Decementation was not observed with RMGIC. Air abrasion did not seem to clinically decrease the decementation risk. The 5-year difference in the occurrence of minor or major chipping between MZ and PVZ prostheses was statistically significant, but nor for catastrophic fracture.

CONCLUSION: Tooth-supported PVZ prostheses present higher failure and complication rates than MZ prosthesis. The difference in complications is striking when it comes to chipping.

CLINICAL RELEVANCE: Awareness of the outcome differences between different types of zirconia prostheses is important for clinical practice.

Aim: To investigate the frequency of further interventions after root filling during a follow-up of 10 to 11 years, and to compare the outcomes with respect to type of coronal restoration and tooth group.Methods: Data from the Swedish Social Insurance Agency´s register of dental treatments were obtained to identify the teeth registered as root filled in Sweden 2009. Type of coronal restoration within 6 months after root filling, as well as the frequency of further interventions (nonsurgical retreatment, periradicular surgery, extraction, further direct and indirect restoration) were tracked in the data register until December 31, 2019. Descriptive statistics and Chi-square tests were used for statistical analysis.Results: Of the 215 611 teeth root filled in 2009, nonsurgical retreatment, periradicular surgery, and extraction were registered for 3.5%, 1.4% and 20%, respectively. The highest frequency of nonsurgical retreatment was registered for molars (4.2%), and periradicular surgery was most frequent in maxillary canines and incisors (2.3%). The highest frequency of extractions was registered for mandibular molars (25.1%). Directly restored teeth had higher frequency of nonsurgical retreatment (3.9%) and extraction (20.8%), compared to indirectly restored teeth (1.7% and 13.6%, respectively; P < 0.001). Of teeth restored with direct restoration within 6 months after root filling, 41.5% were registered with at least one further direct restoration and 14.7% with an indirect restoration. In the group of indirectly restored teeth, 9.3% and 7.1% underwent further restorative treatment with direct and indirect restoration, respectively. The differences registered between directly and indirectly restored root filled teeth were statistically significant (P < 0.001).Conclusions: The frequencies of nonsurgical retreatment and periradicular surgery were low 10 to 11 years after root filling, despite one in five root filled teeth being registered as extracted. Further interventions were significantly more common for directly restored teeth than for those indirectly restored.

Aim: To investigate the fees for root filling and further dental care charged by Swedish dentists during a follow-up period of 10 to 11 years. Comparisons are made between type of restoration registered within 6 months of the root filling, the tooth group, and the root filled teeth that survived versus those that were extracted.Methods: A total of 215 611 teeth were registered as root filled in the Swedish Social Insurance Agency’s data register in 2009. For each identified tooth, the fees for the following interventions were tracked: initial root filling, coronal restorations, and further dental interventions registered during the follow-up period. The outcomes were analysed with descriptive and analytic statistics, using one-way ANOVA and t-tests. The fees are presented in Euro (€1 = SEK 8.94; 01/01/2012).Results: The total fee for the root fillings was 72 million euros, and the mean fee was €333.6 per root filling. The total mean fee for the preservation of a root filled tooth over 10 to 11 years was €923.4, which included root canal treatment, coronal restorations, and further interventions. The mean fee for indirectly restored root filled teeth was higher (€1 279.3) than for those directly restored (€829.4) and for teeth without specified restorations (€832.7; P < 0.001). Molars had a significantly higher mean fee (€966.4) compared to premolars (€882.8) and anterior teeth (€891.3; P < 0.001). The mean fee for teeth that were extracted was higher (€1 225.3) than for those that survived the follow-up (€848.0; P < 0.001). Conclusions: Fees for root filled teeth have accumulated over time probably due to further dental care needed. The total mean fee was significantly higher for indirectly restored root filled teeth than for directly restored. However, prospective clinical cost-effectiveness studies are needed to analyse the total costs.

Objectives: Method-dependent comparison of antimicrobial agents' efficacy against oral pathogens.

Materials and methods: Several sodium hypochlorite solutions (NaOCl)-Perisolv®, Carisolv® and Dakin's solution-were equated with chlorhexidine (CHX) and hydrogen peroxide (H2O2) against ten oral micro-organisms related to caries and periodontitis using different minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) techniques. Agents were adjusted to the final 70 mmol/L concentration of active chlorine molecule.

Results: Apart from H2O2 and the amino acids of Perisolv®, all the agents revealed an antimicrobial effect. Agar diffusion test ranked CHX (p < 0.05) as the most effective against all ten specimens, followed by the NaOCl of Perisolv® and Dakin's solution. Correspondingly, in broth microdilution on agar, CHX was the most effective in eradicating micro-organisms at 0.03 mmol/L compared with 2.2 mmol/L of Dakin's solution. In contrast, the bactericidal concentration of Dakin's solution was the most effective at 0.2 mmol/L, (p < 0.001), followed by Perisolv® (2.14 mmol/L), CHX (2.38 mmol/L) and Carisolv® (3.33 mmol/L) after 5 and 10 min in broth dilution test. In live/dead analysis, 60-min exposure to a 2-fold concentration of agents resulted in two-log Aggregatibacter actinomycetemcomitans inhibition by CHX (35 mmol/L) whilst Streptococcus mutans was more susceptible, in 0.8 and 8.8 mmol/L, after 10 min to CHX and Dakin's respectively.

Conclusion: Replacement of CHX with tested hypochlorite agents showed evident potential and promoted rapid antimicrobial effect.

Clinical relevance: Effective antimicrobial agents are crucial in controlling pathogen-induced oral infections increasing clinical possibilities to combat oral biofilms. Additionally, CHX substitution with hypochlorite agents could eliminate CHX's adverse effects.

Background: Overload from bruxism may affect survival of dental implants.

Objectives: To evaluate implant failure and marginal bone loss (MBL) in patients presenting with probable bruxism compared to non-bruxers. The study was registered in PROSPERO (CRD42021238397).

Methods: An electronic search September 2022 in PubMed/Medline, Web of Science and Science Direct was combined with a hand search. Two independent reviewers carried out abstract screening, full-text assessment, quality assessment (National Institutes of Health tool) and data extraction. Only studies that provided information on self-report and clinical examination needed for the diagnosis of at least 'probable' bruxism were included. A pairwise random-effect meta-analysis was carried out.

Results: In total 1338 studies were identified, and after screening and full-text assessment 27 studies that presented data on 2105 implants in probable bruxers and 10 264 implants in non-bruxers were included, with 138 and 352 implant failures in respective groups. the meta-analysis showed that implants placed in probable bruxers had a higher risk of failure than in non-bruxers (OR 2.189; 95% CI 1.337, 3.583, p = .002). A meta-regression showed that follow-up time did not affect this OR. Eighteen studies provided general data on MBL but did not report results separated between bruxers and non-bruxers. Therefore, an analysis of MBL was not possible.

Conclusion: The results of the present systematic review show that implants placed in probable bruxers present a significantly higher risk of failure than implants placed in non-bruxers. This should be considered in treatment planning and management of implant patients.

Background: To describe the frequency and impact of oral lesions and professional dental care costs in patients with inflammatory bowel disease (IBD) (i.e., Crohn disease [CD] or ulcerative colitis [UC]) compared to matched controls).

Methods: IBD patients and matched controls were surveyed on general anamnestic information, eating and drinking habits, and oral health- and dental care-related questions; IBD patients were additionally surveyed on oral lesions. Problems related to oral lesions and the amount of money spent for professional dental care in the past 12 months were defined as primary outcome parameters.

Results: Answers from 1108 IBD patients and 3429 controls were analyzed. About 30% of the patients indicated having had problems with oral lesions, with CD patients having 46% higher odds and having them more often in a generalized form compared to UC patients. Further, self-reported severe periodontitis increased the odds of having oral lesions by almost 2.3-times. However, only about 12.5% of IBD patients were informed by their physician about oral lesions and about 10% indicated receiving treatment for them. Compared to controls, IBD patients required more often dental treatment and spent more money; specifically, UC and CD patients had 27 and 89% higher odds, respectively, for having spent ≥3000 DKK (ca. 440 USD) at the dentist compared to controls.

Conclusions: IBD patients have more often oral health problems and higher expenses for professional dental care compared to matched controls. This included problems with IBD-related oral lesions, but these are rarely addressed by the medical or dental team.Keywords: Crohn disease; case-control studies; colitis; dental care; inflammatory bowel diseases; surveys and questionnaires; ulcerative.

Radiographic imaging of the mandibular third molar (M3) is a valuable diagnostic tool. It provides information on tooth position, root morphology, and relations to surrounding anatomical structures that facilitates diagnosis and treatment planning. Three modalities are commonly used in dentistry: intraoral and panoramic radiography, and cone beam computed tomography (CBCT). Over time, panoramic radiography became a justified choice in most cases of M3 removal. In the last decade, a three-dimensional (3D) alternative, CBCT, has seen increasing use. The advantages of 3D come at the cost of higher radiation doses and societal expense. The four studies in this thesis originated from current knowledge gaps and clinical needs.

The use of panoramic radiography for evaluating the M3 and its relation to the inferior alveolar nerve (IAN) is well-established practice; however, its application has declined over time, possibly due to the rising popularity of CBCT imaging. Thus, it is of interest to investigate the suitability of panoramic imaging of the M3. Choice of imaging modality is important from dose delivery and socioeconomic standpoints. A survey of clinician experiences and preferences in imaging modalities for pre-surgical analysis was needed.

In diagnostic imaging, the common goal is to reduce radiation exposure to the lowest threshold that still delivers reliable diagnostic information. Due to the growing use of CBCT, there is a need to optimize exposure settings and use reliable measurement methods in dosimetric analysis. Nevertheless, for the M3, the present literature has neither evaluated a low-dose protocol in a clinical setting nor compared the standard method of measuring absorbed dose in dental CBCT with an alternative method.

This thesis is based on the following papers:

Paper I, an observational study, evaluated M3 characteristics and IAN relation, incidental findings, and image quality regarding patient positioning on 442 panoramic radiographs. 

Key findings: A majority of M3s were erupted and vertically positioned, regardless of age. The IAN was located inferior to the roots in just over half of the cases; an overlapping position was most common if the tooth was retained or semi-retained, or patient age less than 30 years. Frequent incidental findings were apical radiolucencies, idiopathic osteosclerosis, and tooth fragments. Patient positioning was suboptimal in one-third of the radiographs; common errors included patient placement posterior to the image layer and an upward-tilted head. 

Paper II was a web-based questionnaire sent to general dentists and to residents and specialists in oral and maxillofacial surgery. The survey comprised multiple-choice questions with four M3 cases depicted in images. 

Key findings: A majority of respondents received a report within 2 weeks of their CBCT referral and would read it and view the images before surgery; one-third did not. Panoramic radiographs were the preferred modality in pre-surgical planning; differences between professions were significant. Panoramic radiographs and CBCT were seen as facilitating treatment planning, and CBCT as also reducing post-operative complications. CBCT tended to be preferred in more complex M3 cases. 

Paper III was a clinical trial investigating an alternative, low-dose CBCT protocol with lower tube current than the default protocol. After justification for CBCT, 48 patients (62 M3s) referred for a pre-surgical investigation were recruited. Two scans of each site were made using the two protocols

Key findings: No significant differences occurred in visibility of root and mandibular canal relationship and proximity, root morphology, and possible root resorption of the second molar. Visibility of the periodontal ligament was significantly better in default images. Subjective image quality in low-dose images (60% less radiation) was acceptable in most cases. 

Paper IV was a laboratory study comparing two dosimeters in a CBCT scan of the M3 region. Five slices of an anthropomorphic phantom were prepared with thermoluminescent dosimeters (TLD-100) at 75 sites and covered with Gafchromic film LD-V1. 

Key findings: Point dose measurements at all TLD sites correlated well with doses measured on film; agreement was better at lower doses. Minimum and maximum doses on film versus at TLD sites deviated greatly on all slices and for several organs. 

To conclude, panoramic radiography is useful in evaluating M3 and IAN relationships. Clinicians consider pre-surgical information to differ depending on imaging modality; modality preference seems to depend on case complexity. Optimized CBCT protocols can be used for the M3. Gafchromic film is a favorable alternative in dental CBCT dosimetry

Objectives: We aimed to map the correlation between thermoluminescent dosimeters (TLDs) and Gafchromic film for measuring absorbed doses and to compare minimum, maximum, and mean absorbed doses over larger regions of interest and at various craniofacial organs and tissues during cone beam computed tomography (CBCT) exposure of the mandibular third molar region.

Study design: We positioned TLDs at 75 measurement points in a head phantom. Gafchromic film was cut to the same shape as the 5 levels of the phantom and was placed on top of the TLDs. Both dosimetry methods thus included the surface of each level simultaneously. CBCT scans were made using a 5 × 5 cm field of view and a rotation angle of 200°. Measurements included absorbed dose distributions, doses at all 75 points, and minimum, maximum, and mean doses within organs and tissues.

Results: The correlation of point-dose measurements at all TLD sites with doses measured on film was strong (R2 = 0.9687), with greatest correlation at lower doses (<2 mGy). Large deviations between TLD and film measurements of minimum and maximum doses and absorbed doses to the organs occurred at all 5 levels. TLD positioning failed to cover several organ sites; for these, only absorbed dose measurements from the film were available.

Conclusions: TLDs were unable to sample dose distributions and gradients accurately. The characteristics of Gafchromic LD-V1 film make it a favorable alternative in dental CBCT dosimetry.

AIM: Triggering receptor expressed on myeloid cells 1 (TREM-1) and peptidoglycan recognition protein 1 (PGLYRP1) are elevated in biofluids in the presence of various inflammatory conditions. This cross-sectional study aimed to evaluate the effect of age, sex, smoking and different oral and systemic non-communicable diseases on the levels of TREM-1 and PGLYRP1 in saliva.

MATERIALS AND METHODS: In total, 445 individuals (mean age 48.7 ± 16.9 years, female:male 51%:49%) were included. All provided self-reported information on smoking and systemic diseases and whole stimulated saliva. Periodontal and cariological parameters were recorded. Salivary levels of TREM-1, PGLYRP1 and total protein were measured using commercially available assays.

RESULTS: Salivary TREM-1 levels were significantly higher in stages III-IV periodontitis compared to other periodontal diagnoses (p < .05). Smoking, bleeding on probing (BOP), percentage of pockets ≥4 mm and the number of manifest caries were associated with TREM-1 (p < .05), while sex, BOP, number of manifest caries and muscle and joint diseases were associated with PGLYRP1 (p < .05).

CONCLUSIONS: Salivary TREM-1 is associated with periodontitis and caries, while PGLYRP1 is associated with gingival inflammation and caries. Additionally, TREM-1 levels are modified by smoking, while PGLYRP1 is modified by sex and muscle and joint diseases. TREM-1 and PGLYRP1 in saliva could serve as potential biomarkers for detecting and monitoring non-communicable diseases.

BACKGROUND: Primary headache syndromes such as migraine are among the most common neurological syndromes. Chronic facial pain syndromes of non-odontogenic cause are less well known to neurologists despite being highly disabling. Given the pain localization, these patients often consult dentists first who may conduct unnecessary dental interventions even if a dental cause is not identified. Once it becomes clear that dental modalities have no effect on the pain, patients may be referred to another dentist or orofacial pain specialist, and later to a neurologist. Unfortunately, neurologists are also often not familiar with chronic orofacial pain syndromes although they share the neural system, i.e., trigeminal nerve and central processing areas for headache disorders.

CONCLUSION: In essence, three broad groups of orofacial pain patients are important for clinicians: (i) Attack-like orofacial pain conditions, which encompass neuralgias of the cranial nerves and less well-known facial variants of primary headache syndromes; (ii) persistent orofacial pain disorders, including neuropathic pain and persistent idiopathic facial/dentoalveolar pain; and (iii) other differential diagnostically relevant orofacial pain conditions encountered by clinicians such as painful temporomandibular disorders, bruxism, sinus pain, dental pain, and others which may interfere (trigger) and overlap with headache. It is rewarding to know and recognize the clinical picture of these facial pain syndromes, given that, just like for headache, an internationally accepted classification system has been published and many of these syndromes can be treated with medications generally used by neurologists for other pain syndromes.

PURPOSE: To evaluate the survival rate of full-coverage tooth-supported fixed prosthetic restorations, single crowns (SCs), and fixed dental prostheses (FDPs), taking into consideration the potential influence of tooth-vitality, presence and type of post, and type of prosthetic restoration material.

MATERIALS AND METHODS: In October 2022, two authors independently conducted a search in PubMed, Web of Science, and Scopus electronic databases as well as a hand search to identify clinical human studies on full-coverage SCs and FDPs supported by vital and/or non-vital abutments and/or a combination of both, with a minimum observation period of 24 months.

RESULTS: Out of 4198 studies identified through the database search and 22 through hand searching, 26 studies fulfilled the inclusion criteria and were included in the analysis of the present systematic review. Included studies scored six points and more according to Newcastle-Ottawa Scale (NOS). The highest estimated 5-year survival rate was observed for (metal-ceramic and all-ceramic) SCs on vital teeth (98.3%; 95% CI [98.1, 98.6%]) and all ceramic SCs on non-vital teeth with fiber post (95.0%; 95% CI [94.5-95.4%]). Metal-ceramic SCs on vital teeth (97.1%; 95% CI [95.6-98.7%]) showed a statistically significant higher estimated 5-year survival rate compared to metal-ceramic SCs with cast metal post (90.7%; 95% CI [87.4-94.0%], P < 0.001), fiber post (91.3%; 95% CI [90.9-91.6%], P < 0.001) and without post (85.7%; 95% CI [80.7, 90.6%], P < 0.032). All-ceramic SCs with fiber post had a statistically significant higher estimated 5-year survival rate (95.0%; 95% CI [94.5-95.4%]) compared to metal-ceramic SCs on non-vital teeth with fiber post (91.3%; 95% CI [90.9-91.6%], P < 0.001). SCs (all-ceramic and metal-ceramic) with fiber post had a statistically significantly higher estimated 5-year survival rate of (92.7%; 95% CI [92.4-92.9%]) than SCs made of metal-ceramic and retained by cast metal post (90.7%; 95% CI [87.4-94.0%], P < 0.001). For FDPs, the 5-year survival rate was significantly higher for FDPs on vital abutments (84.9%; 95% CI [75.9, 93.9%]) compared to FDPs retained by non-vital abutment/s (81.3%; 95% CI [80.3, 82.2%], P = 0.049) irrespective to presence, type of post, and FDPs material. The results are limited by the limited number of studies and the presence of uncontrolled confounding clinical variables.

CONCLUSIONS: Within the limitations of the study, tooth vitality is suggested to contribute positively to the survival of SCs and FDPs.

INTRODUCTION: Oral appliance (OA) therapy in obstructive sleep apnea (OSA) could be a risk factor for normal jaw function, given the prolonged effect of an OA in keeping the mandible in a protruded position away from a normal position. This study aimed to assess changes in symptoms and clinical findings related to jaw function after 1 year of treating OSA with an OA.

METHODS: In this follow-up clinical trial, 302 patients with OSA were assigned to treatment with either monobloc or bibloc OA. Baseline and 1-year follow-up assessment included using the Jaw Functional Limitation Scale, self-reported symptoms and signs related to jaw function. The clinical examination of jaw function included mandibular mobility, dental occlusion, and tenderness in the temporomandibular joints and masticatory muscles. Descriptive analyses of variables are presented for the per-protocol population. To evaluate differences between the baseline and the 1-year follow-up, paired Student t tests and the McNemar change test was used.

RESULTS: One-hundred and ninety-two patients completed the 1-year follow-up (male 73%, mean aged 55 ± 11 years). There was no change in the Jaw Functional Limitation Scale score at the follow-up (nonsignificant). The patients described no change in symptoms at the follow-up, except for improvements in morning headache (P <0.001) and increased frequency of difficulties in opening the mouth or chewing on awakening (P = 0.002). Subjectively reported changes in dental occlusion during biting/chewing increased significantly at the follow-up (P = 0.009).

CONCLUSIONS: No changes in measurements of jaw mobility, dental occlusion, or pain on palpation of the temporomandibular joints or masticatory muscles were seen at the follow-up. Thus, using an OA in treating OSA had limited influence on jaw functions and related symptoms. Moreover, the risk of developing pain and functional impairment in the masticatory system was infrequent, indicating that this treatment is safe and can be recommended.

Objective: To map oral health-related standard of care in the context of head and neck cancer (HNC) treatment across the European Union (EU).

Materials and Methods: Six hundred and ninety centers across the European Union were contacted. The questionnaire contained questions focusing on the team/department structure, HNC treatment planning routines, and assessment and handling of dental treatment needs prior to cancer treatment.

Results: Eighty-seven centers across the EU responded. Department structure and number of HNC patients treated per year varied widely and dental professionals are included as part of the team in about 25% of the centers. Standard of care, in terms of dental assessment and preventive dentistry routines, such as recording an orthopantomogram, offering dental treatment, and providing a radiation protection splint and splint for fluoride application, differed significantly among the European regions. Independent of the region, these aspects are positively affected if dental professionals are part of the interdisciplinary treatment team and if dental treatment is offered within the center.

Conclusion: Dental professionals are still only to a very limited extent included in interdisciplinary treatment planning teams of HNC patients. However, their inclusion and/or offering dental treatment within the same hospital/center appears to improve oral health-related standard of care.

Clinical Relevance: Inclusion of dental professionals in treatment planning teams of HNC patients appears to improve oral health-related standard of care within HNC treatment.

Background: Excessive jaw muscle activity is a frequent complication after acquired brain injury (ABI).

Objective: The study aimed to identify the occurrence and severity of jaw muscle activity and its association with altered state of consciousness in patients with ABI.

Methods: A total of 14 severe ABI patients with varied altered state of consciousness were recruited. A single-channel electromyographic (EMG) device was used to assess the jaw muscle activity for three consecutive nights during Week 1 and Week 4 following admission. Differences in number of EMG episodes/h between Week 1 and 4 were analysed using non-parametric tests and association between the EMG activity and altered state of consciousness were analysed using Spearman's correlation test.

Results: Nine of fourteen (64%) patients showed indications of bruxism (cutoff: >15 EMG episodes/h). The average EMG episodes/h at admission were 44.5 ± 13.6 with no significant changes after Week 4 of admission (43 ± 12.9; p = .917). The EMG episodes/h ranged from 2 to 184 during Week 1 and 4-154 during Week 4. There were no significant correlations between the number of EMG episodes/h during the three nights and the individuals altered state of consciousness during Week 1 and Week 4.

Conclusion: Patients with ABI had a conspicuously high but variable level of jaw muscle activity at admission and it tend to remain high after 4 week of hospitalisation which could potentially lead to adverse effects such as excessive tooth wear, headaches and pain in jaw muscles. The lack of associations between individuals altered level of consciousness and EMG activity could be due to low sample size and further studies are clearly warranted in this patient group with special needs. Single-channel EMG devices can record jaw muscle activity early in the hospitalisation period and might be a helpful tools for early detection of bruxism in ABI patients.

Objectives: The aim of this study was to monitor changes in Osteoprotegerin (OPG) and receptor activator of nuclear factor-kappa ligand (RANKL) levels in the saliva during orthodontic tooth movement (OTM). Materials and Methods: Nine healthy females (15-20 y of age) with four pre-molar extractions and fixed appliance were included. In total, 134 stimulated and 134 unstimulated saliva samples were collected: at baseline and then every 6-8 weeks at follow-up appointments during the whole orthodontic treatment. Twelve age-matched females with no active orthodontic treatment served as a control group. Saliva samples were analysed by enzyme-linked immunosorbent assay (Elisa). The mean levels of OPG and RANKL were calculated according to the different orthodontic treatment stages: alignment, space closure and finishing. A mixed model analysis was used to compare the means of treatment stages. Baseline OPG levels were compared with the control group using an independent t-test. OPG levels were measured in stimulated saliva due to low levels in unstimulated saliva. Results: No significant difference was observed between baseline OPG values and the control group. OPG increased significantly at all treatment stages: alignment, space closure and finishing compared with baseline (P = 0.002, P = 0.039, P = 0.001, respectively). The salivary levels of OPG increased gradually, except during space closure, reaching peak levels at finishing. RANKL was undetectable in stimulated and unstimulated saliva by sandwich Elisa during OTM. Conclusions: This novel approach shows the changes in the levels of OPG in OTM and indicates how and when to sample saliva during orthodontic treatment to analyse bone remodelling.

BackgroundThe functional integration of the jaw and neck motor systems, of great importance to everyday oral activities, is established in early childhood. Detailed characterisation of this developmental progress is largely unknown. ObjectiveTo establish developmental changes in jaw-neck motor function in children over the ages 6-13 years compared to adults. MethodsJaw and head movement kinematics during jaw opening-closing and chewing were longitudinally recorded in 20 Swedish children (8 girls) at 6 (6.3 & PLUSMN; 0.4), 10 (10.3 & PLUSMN; 0.3) and 13 (13.5 & PLUSMN; 0.7) years of age and 20 adults (9 women, 28.2 & PLUSMN; 6.7). Movement amplitudes, jaw movement cycle time (CT), coefficient of variation (CV) and head/jaw ratio for amplitudes were analysed. Linear mixed effect analysis and Welch's t-test were used. ResultsChildren showed pronounced movement variability and longer CT at 6 and 10 years old during opening and chewing (p < .001). Compared to adults, 6-year-olds showed higher head/jaw ratios (p < .02) and longer CT (p < .001) during opening and chewing, and higher CV-head (p < .001) during chewing. Whereas 10-year-olds showed larger jaw and head amplitudes (p < .02) and longer CT (p < .001) during opening, and longer CT (p < .001) and higher CV-head (p < .001) during chewing. For 13-year-olds, longer CT (p < .001) during chewing was found. ConclusionChildren showed pronounced movement variability and longer movement cycle time at 6-10 years and developmental progress in jaw-neck integration from 6 to 13 years, with 13-year-olds displaying adult-like movements. These results add new detailed understanding to the typical development of integrated jaw-neck motor function.

Periodontal diseases include pathological conditions elicited by the presence of bacterial biofilms leading to a host response. In the diagnostic process, clinical signs such as bleeding on probing, development of periodontal pockets and gingival recessions, furcation involvement and presence of radiographic bone loss should be assessed prior to periodontal therapy, following active therapy, and during long-term supportive care. In addition, patient-reported outcomes such as increased tooth mobility, migration, and tilting should also be considered. More important to the patient, however, is the fact that assessment of signs of periodontal diseases must be followed by an appropriate treatment plan. Furthermore, it should be realized that clinical and radiographic periodontal diagnosis is based on signs which may not reflect the presence of active disease but rather represent the sequelae of a previous bacterial challenge. Hence, the aim of the present review is to provide a summary of clinical and radiographic diagnostic criteria required to classify patients with periodontal health or disease.

Objectives: To assess the impact of implantoplasty (IP) on maximum implant failure strength of narrow diameter implants of different type/design and material, with simulated advanced bone loss.

Materials and Methods: Narrow, parallel-walled implants (3.3 mm in diameter x 10 mm long) with an internal connection of different type/design [bone level (BL), tissue level (TL)] and material [Titanium grade IV (Ti), Titanium-Zirconium alloy (TiZr)] from one specific manufacturer were used. Half of the implants were subjected to IP in their coronal 5 mm; the remaining were used as controls (seven implants per group). Dynamic loading prior to maximum load strength testing was included.

Results: During dynamic loading, the fracture rate of BL implants was low and independent of IP, while that of TL implants increased significantly with IP compared with controls (p = .001). Maximum implant failure strength reduction (in %) due to IP, was 1.3%-25.4%; TiZr BL implants were least affected. Implants subjected to IP compared to those without IP as well as TL implants compared to BL implants showed a significantly lower maximum implant failure strength (p < .002); implant material was not significant (p = .845).

Conclusions: Based on data from implants of one specific manufacturer, IP has a significant negative impact on the fracture strength of narrow implants suffering from advanced peri-implantitis. TL implants have been more severely affected compared to BL implants and presented an increased risk for failure during normal chewing forces. In addition, this negative impact of IP on TL implants was independent of the implant material (i.e., Ti or TiZr).

Clinical Relevance: Narrow single TL implants with advanced horizontal bone loss (e.g., 5 mm), when subjected to IP, appear to have an increased fracture risk during normal function.

Objective: The study aimed to compare self-perceived oral health and orofacial appearance in three different cohorts of 60-year-old individuals. Method: A cross-sectional design, based on data obtained from a questionnaire used in the Swedish National Study of Aging and Care. The sample comprised 478 individuals, from baseline, 2001-2003 (n = 191), 2007-2009 (n = 218) and 2014-2015 (n = 69). Comparisons were made within and between the cohorts, with bivariate analysis and Fisher's exact test. Statistical significance was considered at p < 0.05. Results: The result showed that a low number of the participants reported self-perceived problems with oral health. Of the problems reported, a higher proportion in cohort 2014-2015 (39.3%) experienced problems with bleeding gums. The experience of bleeding gums increased between the cohorts 2001-2003 and 2014-2015 (p = 0.040) and between 2007-2009 and 2014-2015 (p = 0.017). The prevalence of discomfort with sensitive teeth was experienced in 7%-32%. Twice as many women compared to men experienced discomfort in all cohorts (no significant differences between the cohorts). Satisfaction with dental appearance was experienced in 75%-84%. Twice as many women compared to men were dissatisfied with their dental appearance in 2001-2003 (p = 0.011) and with discoloured teeth (p = 0.020). No significant differences could be seen between the cohorts regarding discomfort with dental appearance or discoloured teeth. Conclusion: The 60-year-olds irrespective of birth cohort, perceived their oral health and orofacial appearance as satisfactory.

Probiotic bacteria show promising results in prevention of the biofilm-mediated disease caries, but the mechanisms are not fully understood. The acid tolerance response (ATR) allows biofilm bacteria to survive and metabolize at low pH resulting from microbial carbohydrate fermentation. We have studied the effect of probiotic strains: Limosilactobacillus reuteri and Lacticaseibacillus rhamnosus on ATR induction in common oral bacteria. Communities of L. reuteri ATCC PTA5289 and Streptoccus gordonii, Streptococcus oralis, Streptococcus mutans or Actinomyces naeslundii in the initial stages of biofilm formation were exposed to pH 5.5 to allow ATR induction, followed by a low pH challenge. Acid tolerance was evaluated as viable cells after staining with LIVE/ DEAD & REG;BacLightTM. The presence of L. reuteri ATCC PTA5289 caused a significant reduction in acid tolerance in all strains except S. oralis. When S. mutans was used as a model organism to study the effects of additional probiotic strains (L. reuteri SD2112, L. reuteri DSM17938 or L. rhamnosus GG) as well as L. reuteri ATCC PTA5289 supernatant on ATR development, neither the other probiotic strains nor supernatants showed any effect. The presence of L. reuteri ATCC PTA5289 during ATR induction led to down-regulation of three key genes involved in tolerance of acid stress (luxS, brpA and ldh) in Streptococci. These data suggest that live cells of probiotic L. reuteri ATCC PTA5289 can interfere with ATR development in common oral bacteria and specific strains of L. reuteri may thus have a role in caries prevention by inhibiting development of an acid-tolerant biofilm microbiota.